A fully-covered stent (Alimaxx-E) for the palliation of malignant dysphagia: a prospective follow-up study

ORIGINAL ARTICLE: Clinical Endoscopy

A fully-covered stent (Alimaxx-E) for the palliation of malignant dysphagia: a prospective follow-up study Madeleen J. Uitdehaag, RN, MSc, Jeanin E. van Hooft, MD, MSc, Els M. L. Verschuur, RN, PhD, Alessandro Repici, MD, PhD, Ewout W. Steyerberg, PhD, Paul Fockens, MD, PhD, Ernst J. Kuipers, MD, PhD, Peter D. Siersema, MD, PhD Rotterdam, Amsterdam, Utrecht, The Netherlands, Milan, Italy

Background: The majority of the currently available metal stents are partially covered to reduce migration risk. However, one of the remaining issues is tissue ingrowth through the uncovered stent parts. Objective: To determine efficacy, recurrent dysphagia, and complications of a fully covered stent, ie, the Alimaxx-E stent, and to compare two stent delivery systems, ie, one introducing the stent over a guidewire and one introducing the stent over a small-caliber endoscope. Design: A prospective, follow-up study evaluating a new stent design, with randomization for type of introduction system. Setting: Three tertiary referral centers. Patients: Forty-five patients with inoperable or metastatic esophageal or gastric cardia cancer. Interventions: Stent placement. Main Outcome Measurements: (1) Functional outcome, recurrent dysphagia, complications, and mortality of the Alimaxx-E stent; (2) functional aspects of the delivery system. Results: At 4 weeks after stent placement, the dysphagia score improved in all patients (P ! .001). Twenty-two of 45 patients (49%) developed among them 28 episodes of recurrent dysphagia, predominantly stent migration (n Z 16). Major complications occurred in 9 of 45 patients (20%), with all 5 early (!1 week) complications (severe pain [n Z 3], hemorrhage [n Z 1], and fever [n Z 1]) occurring in patients in whom the stent was introduced over the endoscope (P Z .02). During follow-up, 44 patients died, 3 (7%) from hemorrhage. Limitation: The Alimaxx-E stent was not randomly compared with other stent designs. Conclusions: Placement of Alimaxx-E stents is safe and produces long-term relief of dysphagia, particularly when introduced over a guidewire. The migration rate of the Alimaxx-E stent is, however, unacceptably high, and an adapted stent design is needed. (Gastrointest Endosc 2009;70:1082-9.)

Self-expanding metal or plastic stents are frequently used for the relief of dysphagia from inoperable esophageal or gastric cardia cancer.1,2 During the last few years, procedure-related complications and long-term complications of stent placement have remained unchanged, with rates less than 10%3-5 and less than 15%,4,5 respectively. In contrast, recurrent dysphagia after stent placement is Abbreviations: IQR, interquartile range; HR, hazard ratio. DISCLOSURE: All authors disclosed no financial relationships relevant to this publication. Copyright ª 2009 by the American Society for Gastrointestinal Endoscopy 0016-5107/$36.00 doi:10.1016/j.gie.2009.05.032

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a frequently encountered problem, occurring in 30% to 50% of patients, mainly due to nontumoral or tumoral tissue ingrowth and overgrowth, stent migration, and, to a lesser extent, food-bolus obstruction.4,5 The relatively high frequency of recurrent dysphagia has resulted in efforts to improve stent design. Currently, several stent designs are available.4,6 The most commonly used stents worldwide are the metal, partially covered Ultraflex stent (Boston Scientific, Natick, Mass) and the nonmetal (plastic) fully covered Polyflex stent (Boston Scientific). Nontumoral and tumoral tissue ingrowth is a frequently observed cause of recurrent dysphagia with Ultraflex stents,4,5,7,8 whereas stent migration commonly occurs with Polyflex stents.4,5,9-11 A relatively new stent is the fully covered Niti-S www.giejournal.org

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stent (Taewoong Medical, Seoul, Korea), which has an outer nitinol wire that reduces the risk of stent migration.4,12 The newly designed Alimaxx-E stent (Alveolus, Charlotte, NC) is fully covered to resist tissue ingrowth and has 20 struts on the outside to prevent migration (Fig. 1). The stent can be introduced by using 2 different procedures: (1) over a guidewire (Alimaxx-E GW; Alveolus) or (2) by direct vision using a special delivery system with the delivery catheter fitting over a small-caliber endoscope (Alimaxx-E DV; Alveolus). The aim of the current study was to determine functional outcome, recurrent dysphagia, and complications of the Alimaxx-E stent in patients with inoperable esophageal or gastric cardia cancer. Furthermore, stent placement by introducing it over a guidewire or by direct vision was compared for functional aspects.

PATIENTS AND METHODS Between March 2006 and January 2007, all consecutive patients with dysphagia due to esophageal or gastric cardia cancer who met the inclusion and did not meet the exclusion criteria of the study and gave informed consent were treated with an Alimaxx-E stent. Inclusion criteria included an inoperable malignant obstruction of the esophagus or gastric cardia, or recurrent dysphagia after prior radiation with curative or palliative intent for esophageal or gastric cardia cancer. A tumor was considered inoperable if the patient had distant metastases or local tumor infiltration in neighboring organs and/or a poor condition because of concomitant disease. Exclusion criteria included a tumor length of more than 12 cm, tumor growth within 2 cm of the upper esophageal sphincter, a fistula between the esophagus and respiratory tree, and previous stent placement. Patients who were unfit to undergo conscious sedation were also excluded. Finally, 45 patients gave written informed consent, and 2 patients refused to participate in the study. Stent placement was performed at 3 centers: (1) the Erasmus MC – University Medical Center Rotterdam, The Netherlands; (2) the Academic Medical Center Amsterdam, The Netherlands; and (3) the Istituto Clinico Humanitas, Milan, Italy. The institutional review boards at all 3 hospitals approved the study. All patients were evaluated before stent placement and at 4-week intervals after stent placement, until death. Evaluations were performed by scheduled telephone interviews of the patient and included the following items: (1) ability to eat and/or swallow, as assessed by the dysphagia score, graded as, 0 Z ability to eat a normal diet; 1 Z ability to eat some solid food; 2 Z ability to eat some semi-solids only; 3 Z ability to swallow liquids only; and 4 Z complete dysphagia; (2) general health, as assessed by the World Health Organization performance score, graded as, 0 Z normal activity; 1 Z symptoms but ambulatory; 2 Z in bed less than 50% of time; 3 Z in bed more than 50% of time; and 4 Z 100% bedridden; and (3) specific symptoms, www.giejournal.org

Alimaxx-E stent for the palliation of malignant dysphagia

Capsule Summary What is already known on this topic d

Partially covered esophageal stents are susceptible to tissue in-growth but have a low risk of stent migration.

What this study adds to our knowledge d

d

In a prospective follow-up evaluation of a new, fully covered stent in 45 patients with inoperable or metastatic esophageal or gastric cardia cancer, dysphagia scores universally improved at 4 weeks. Twenty-two patients developed 28 episodes of recurrent dysphagia, mostly because of stent migration.

such as pain, heartburn, and weight loss. When indicated, eg, in case of recurrent dysphagia or complications, patients were clinically evaluated and treated.

Stent design The Alimaxx-E stent is made of nitinol, and it is fully covered with polyurethane to resist tissue ingrowth (Fig. 1). The Alimaxx-E stent used in this study had a luminal diameter of 18 or 22 mm. If prestenotic dilation was observed during endoscopy, then a larger-diameter stent was used. The outward force of the stent is most pronounced at the body. The stent has 20 antimigration struts to prevent migration.

Procedure If a tight stricture was present, then the tumor was dilated to a maximum diameter of 12 mm by using Savary dilation or (preferably) a small-caliber (5.9 mm) endoscope (Olympus BV, Zoeterwoude, The Netherlands) was used to allow the tumor to be inspected, the tumor margins to be marked, and a guidewire to be placed. A stent measuring 2- to 4-cm longer than the stricture was chosen to allow for a 1- to 2-cm extension above and below the proximal and distal tumor shoulder. The stent was introduced over a guidewire (Alimaxx-E GW) or by direct vision by using a new delivery system in which the delivery catheter fitted over a small-caliber endoscope (Alimaxx-E DV). The choice for either delivery system was at random, after stratification for previous chemotherapy and/or radiotherapy, and for tumor location. The Alimaxx-E DV features a window at the end of the introduction system to view stent deployment. The size of the introduction catheter of the Alimaxx-E DV is 30F, whereas that of the Alimaxx-E GW is smaller, with a size of 22F. We only used fluoroscopy with the DV introduction system when stent placement was technically difficult and additional information during placement was considered to be indicated.

Statistical analysis The results were expressed as mean (SD), and medians with interquartile range (IQR) and range; survival was Volume 70, No. 6 : 2009 GASTROINTESTINAL ENDOSCOPY 1083

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TABLE 1. Clinical characteristics of 45 patients treated with an Alimaxx-E stent for palliation of dysphagia due to carcinoma of the esophagus or gastric cardia Characteristics

Patients (n Z 45)

Age (y) (mean SD)

63 (11)

Males, no. of patients (%)

33 (73)

Dysphagia score before treatment, median (IQR, range)

3 (1, 2-4)

WHO performance score before treatment, median (IQR, range)

1 (1, 0-4)

Tumor length, cm, mean (SD)

7.1 (2.1)

Tumor location, no. of patients (%) Mid-esophagus

10 (22)

Distal esophagus/gastric cardia

35 (78)

Histology, no. of patients (%) Squamous cell carcinoma

15 (33)

Adenocarcinoma

29 (64)

Unknown Prior radiation and/or chemotherapy, no. of patients (%)

1 (2) 14 (31)

Chemotherapy

8 (18)

Radiation

1 (2)

Both

5 (11)

IQR, interquartile range; WHO, World Health Organization.

Figure 1. Fully covered Alimaxx-E stent with 20 anti-migration struts on the outside (arrows).

expressed as median survival (Kaplan-Meier). Differences in dysphagia score and World Health Organization performance score and weight before treatment and at 1, 3, and 6 months after treatment were analyzed by the Wilcoxon rank sum test. Complications between the 2 introduction systems were compared with the Kaplan-Meier and log-rank test to adjust for time of occurrence of the event and survival differences. Factors influencing the frequency of migration were analyzed with Cox regression analysis with tumor location, introduction system, stent diameter, prior and post radiation, and/or chemotherapy, histology, and tumor length as covariates. A 2-sided P ! .05 was considered statistically significant. All analyses were conducted with SPSS, version 14.0 (SPSS Inc, Chicago, Ill).

GW system (mean 7.7 cm; SD 1.8) than for those treated with the Alimaxx-E DV system (mean 6.4 cm; SD 2.2 [P Z.04]). All other characteristics were not different between the 2 introduction systems.

Procedural characteristics

RESULTS

In total, 22 patients were treated with the Alimaxx-E GW system and 23 with the Alimaxx-E DV system (Table 2). In 11 of 23 (48%) patients treated with the DV system, and in none of the patients treated with the GW system, difficulties were experienced passing the introduction system through the stricture (P !.001). Endoscopic vision through the window at the end of the introduction system of the DV system was poor in 2 patients (9%), which resulted in fluoroscopy-guided stent placement in these patients. The procedural time with the DV system was longer compared with the GW system (16 vs 10 minutes, respectively; P Z .04).

Clinical characteristics

Functional outcome

Clinical characteristics of 45 patients treated with an Alimaxx-E stent are shown in Table 1. The length of the tumor was longer for patients treated with the Alimaxx-E

Functional outcome is shown in Figures 2 to 4. The dysphagia score improved in surviving patients from a median score of 3 before stent placement to a median of 1 at 1

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Alimaxx-E stent for the palliation of malignant dysphagia

TABLE 2. Procedural characteristics of the Alimaxx-E GW and Alimaxx-E DV delivery system ALIMAXX-E ALIMAXX-E P GW (n Z 22) DV (n Z 23) value*

Characteristics Diameter stent, no. of patients (%)

.46

Small (18 mm)

12 (55)

10 (44)

Large (22 mm)

10 (46)

13 (57)

3 (14)

2 (9)

.60

0 (0)

11 (48)

!.001

–

2 (9)

–

Difficulties with deployment stent

0 (0)

3 (13)

.09

Repositioning stent required

5 (23)

5 (22)

.86

Difficulties removing delivery system

3 (14)

1 (4)

.25

22 (100)

2 (9)

!.001

10 (5, 6-30)

16 (8, 6-25)

.04

Dilation before treatment, no. of patients (%) Technical problems, no. of patients (%) Difficulties passing the system through stricture Poor endoscopic vision

Use of fluorosocopy during stent placement, no. of patients (%) Procedure time, min, median (IQR, range)

*Comparing the Alimaxx-E GW with the Alimaxx-E DV introduction system.

Recurrent dysphagia

Figure 2. Mean dysphagia score for a period of time in 45 patients treated with an Alimaxx-E stent for palliation of dysphagia due to carcinoma of the esophagus or gastric cardia.

month, and zero in patients still alive at 6 months after treatment (both intervals: P ! .001). The median World Health Organization performance status remained stable in the first month (score: 1) after stent placement (P Z .05), but slightly deteriorated 6 months after treatment (score: 2) (P ! .01). The median weight remained stable shortly after placement (66 kg) (P Z .05) and had slightly increased 6 months later (70 kg) (P Z .49). www.giejournal.org

Twenty-two of 45 patients (49%) with an Alimaxx-E stent developed 28 episodes of recurrent dysphagia, which was caused by tissue overgrowth (n Z 7), stent migration (n Z 16), food bolus obstruction (n Z 4), or a stent that was not fully deployed (n Z 1) (Table 3). All but 1 stent migrated into the stomach, and these were endoscopically removed, either with a snare or a grasping forceps, without encountering complications. In 1 patient, the stent migrated into the small bowel. This patient refused an endoscopic intervention to remove the stent, and the stent was surgically removed. Three patients had tissue overgrowth at both ends of the stent, and another 4 patients had tissue overgrowth at only the proximal end of the stent. Tissue overgrowth in 6 patients was treated with a second overlapping stent and in 1 patient by radiation therapy to treat concomitant bleeding. Tumor histology, particularly adenocarcinoma, was the only variable in univariable analysis that was associated with an increased risk of stent migration (hazard ratio [HR] Z 5.5; P Z .03); however, in multivariable analysis, no significant effect of any of these variables remained statistically significant (Table 4).

Complications In total, major and minor complications were seen in 17 of 45 patients (38%) treated with an Alimaxx-E stent (Table 3). Of these, 5 major complications occurred shortly (!1 week) after the procedure, all in patients treated with the Alimaxx-E DV system (P Z .02 for Volume 70, No. 6 : 2009 GASTROINTESTINAL ENDOSCOPY 1085

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TABLE 3. Complications and recurrent dysphagia after placement of an Alimaxx-E esophageal stent in 45 patients with dysphagia due to inoperable carcinoma of the esophagus or gastric cardia Complications and recurrent dysphagia Total complications (major–minor), no. of patients (%)

20 in 17 (38)

Major complications, no. of patients (%)

10 in 9 (20)

%7 days

5 in 5 (11)*

Severe pain

3

Hemorrhage

1

Fever

1

Perforation

0

R7 days Figure 3. Mean World Health Organization performance score for a period of time in 45 patients treated with an Alimaxx-E stent for palliation of dysphagia due to carcinoma of the esophagus or gastric cardia.

Patients (n Z 45)

5 in 5 (11)

Severe pain

0

Hemorrhage

2

Fistula

3

Minor complications, no. of patients (%)

10 in 10 (22)

Mild pain

7

Gastroesophageal reflux

3

Recurrent dysphagia, no. of patients (%)

28 in 22 (49)

Stent migration

16

Tissue overgrowth

7

Food bolus obstruction

4

Other

1y

*P Z .02, comparing Alimaxx-E DV with Alimaxx-E GW introduction system. yStent not fully deployed.

Figure 4. Mean weight score (in kg) for a period of time in 45 patients treated with an Alimaxx-E stent for palliation of dysphagia due to inoperable carcinoma of the esophagus or gastric cardia.

GW group (P Z .76). Three patients developed an esophagorespiratory fistula; 2 of the patients at the distal end of the stent and 1 patient at the proximal end, yet all occurred in the setting of a small-diameter stent. In 2 patients, a hemorrhage was detected after 3 and 9 months, respectively, and both patients died from this complication. Minor complications, particularly retrosternal pain and symptoms of gastroesophageal reflux, were seen in 10 of 45 patients (22%) (Table 3). The pain was stent related in all 7 patients. These patients required temporary analgesics but were not admitted to the hospital.

a difference between both systems). Three patients had severe pain within 24 hours after stent placement; these patients were hospitalized for a short period and treated with analgesics. In the fourth patient, hemorrhage occurred 5 days after stent placement, and this patient died from the complication. The fifth patient had a fever develop 1 day after placement, without a focus being detected, and this patient was treated with a short course of antibiotics that helped resolve the fever without complications. Long-term major complications occurred in 5 of 45 patients (11%); 3 in the DV group and 2 in the

Follow-up was updated to August 2008. One patient was still alive at that time. The median survival after stent placement was 146 days (95% CI, 97-195 mm). The

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Survival

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Alimaxx-E stent for the palliation of malignant dysphagia

TABLE 4. Univariable analysis on factors associated with occurrence of migration in 45 patients treated with an Alimaxx-E stent for palliation of dysphagia due to inoperable carcinoma of the esophagus or gastric cardia Univariable analysis* 95% Characteristics

Patients Events (migration)

HR

CI

P value

0.7-14

.14

0.1-1.5

.18

0.6-4.7

.36

Tumor location Mid-esophagus

10

2

1

Distal esophagus/gastric cardia

35

13

3.1

No

31

12

1

Yes

14

3

0.4

No

35

9

1

Yes

10

6

1.6

Squamous cell carcinoma

15

2

1

Adenocarcinoma

29

13

5.5

1.2-25

.03

0.9

0.7-1.2

.60

.19

Prior chemotherapy and/or radiation

Post chemotherapy

Tumor histology

Tumor length (per cm) Stent introduction system Guidewire (GW)

22

9

1

Over the scope (DV)

23

6

0.50 0.2-1.4

Small

22

5

1

Large

23

10

2.7

Stent diameter

0.9-8.0

.07

HR, hazard ratio; CI, confidence interval. *None of these issues remained significantly different in multivariable analysis.

majority of patients died as a result of tumor progression (n Z 40 [89%]). Three patients (7%) died from hemorrhage, which could have been related to the stent but was more likely related to tumor characteristics and/or progression, and 1 patient died from an unrelated cause.

DISCUSSION In this prospective follow-up series of 45 patients treated with an Alimaxx-E stent for dysphagia due to inoperable carcinoma of the esophagus or gastric cardia, we showed that this new stent design provided good symptomatic relief of malignant dysphagia. Placement of an Alimaxx-E stent was also safe and was not associated with a higher incidence of complications compared with those www.giejournal.org

found in previous studies with other stent designs, ie, Niti-S stents, Polyflex stents, and Ultraflex stents.4,5,9,12,13 However, the most remarkable finding was the rather high incidence of recurrent dysphagia due to stent migration (Table 3). This finding was somewhat unexpected in this group of patients with a stenotic esophageal or gastric cardia carcinoma. Stent migration was only associated with tumor histology, particularly adenocarcinoma, but not with other tumor- or stent-related factors in univariate analysis (Table 4). Nevertheless, because all adenocarcinomas were located in the distal esophagus, tumor location probably played a role in the high migration rate.13,14 This may also explain why the migration rate was higher, although not significantly, with large-diameter stents compared with small-diameter stents. This is in contrast to findings in the literature.7,8,15 Large-diameter stents were, Volume 70, No. 6 : 2009 GASTROINTESTINAL ENDOSCOPY 1087

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however, more often placed across the gastroesophageal junction (21 of 23) than were small-diameter stents (9 of 22), which may well account for this finding. In addition, it seems likely that the high migration rate of the AlimaxxE stent was also caused by characteristics of the stent itself, particularly the fact that the stent is fully covered to allow removal if indicated. Although the Alimaxx-E stent is flared, has an outward force that is most pronounced at the stent body, and has 20 struts on the outside of the stent, these features were probably not sufficient to prevent migration. An adapted stent design with 45 struts instead of 20 has recently been introduced. Our own (preliminary) experience suggests that the results of the migration rate with the adapted Alimaxx-E stent are reduced. Recurrent dysphagia due to nontumoral or tumoral tissue overgrowth was found in 7 patients (16%). This is in line with tissue ingrowth or overgrowth rates reported with the Polyflex stent (10%-20%), but this rate is lower than those reported with another fully covered metal stent, ie, the Niti-S stent (24%), and a partially covered metal stent, ie, the Ultraflex stent (up to 31%).4,5,9,16,17 Mayoral et al18 found that in almost half of the patients with tissue ingrowth or overgrowth, the cause was nontumoral tissue, mainly granulation tissue formation. Stent characteristics, such as radial force, stent diameter, and contact of the esophageal mucosa with the exposed metal stent part, have all been suggested to play a causative role in nontumoral tissue growth.18 As previously mentioned, the major complication rate in this study was similar to that observed with other recently introduced stents. Remarkably, all early (!1 week) major complications occurred with stents placed with the DV delivery system. We noted that passing this delivery system through a stenotic tumor was more difficult compared with the GW delivery system. The DV system has a diameter of 30F, whereas that of the GW delivery system is 22F. The fact that the DV delivery system is also rather rigid explains why placing stents with this system is associated with an increased risk of procedurerelated complications. The characteristics of the DV system are not very much different from those of the formerly used delivery systems for placement of plastic endoprostheses, which have also been shown to be associated with a high procedure-related complication rate.19,20 Therefore, we suggest an improvement of the design of the DV delivery system; however, as the system is made to fit over a small-caliber endoscope, the feasibility of this seems unlikely. Although the outward force of the stent was less pronounced at both ends than at the body, remarkably, 3 patients (7%) had fistula formation develop at the stent end. Nonetheless, this occurrence rate and the time interval between stent placement and fistula formation, after 4, 5, and 13 months, respectively, were not different from those reported in other series in which fistula formation was observed in as many as 9% of patients after a similar

follow-up period.4,5,14 Therefore, the most likely cause of fistula formation was tumor progression, possibly in combination with pressure on the esophageal mucosa exerted by the flared stent ends. In conclusion, the Alimaxx-E stent provides relief of dysphagia from esophageal and gastric cardia cancer; however, the initial design was associated with a high incidence of stent migration. It is unclear whether this stent offers any true clinical advantages in comparison with existing partially covered stents. Comparative studies with other stent designs are needed. Because the risk of procedure-related complications was lower and the placement was easier with the GW system compared with the DV system, we strongly recommend the former system for stent placement.

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REFERENCES 1. Homs MY, Kuipers EJ, Siersema PD. Palliative therapy. J Surg Oncol 2005;92:246-56. 2. Siersema PD. Treatment options for esophageal strictures. Nat Clin Pract Gastroenterol Hepatol 2008;5:142-52. 3. Sabharwal T, Hamady MS, Chui S, et al. A randomised prospective comparison of the Flamingo Wallstent and Ultraflex stent for palliation of dysphagia associated with lower third oesophageal carcinoma. Gut 2003;52:922-6. 4. Verschuur EM, Repici A, Kuipers EJ, et al. New design esophageal stents for the palliation of dysphagia from esophageal or gastric cardia cancer: a randomized trial. Am J Gastroenterol 2008;103:304-12. 5. Conio M, Repici A, Battaglia G, et al. A randomized prospective comparison of self-expandable plastic stents and partially covered selfexpandable metal stents in the palliation of malignant esophageal dysphagia. Am J Gastroenterol 2007;102:2667-77. 6. Siersema PD, Marcon N, Vakil N. Metal stents for tumors of the distal esophagus and gastric cardia. Endoscopy 2003;35:79-85. 7. Homs MY, Steyerberg EW, Eijkenboom WM, et al. Single-dose brachytherapy versus metal stent placement for the palliation of dysphagia from oesophageal cancer: multicentre randomised trial. Lancet 2004;364:1497-504. 8. Siersema PD, Hop WC, van Blankenstein M, et al. A comparison of 3 types of covered metal stents for the palliation of patients with dysphagia caused by esophagogastric carcinoma: a prospective, randomized study. Gastrointest Endosc 2001;54:145-53. 9. Conigliaro R, Battaglia G, Repici A, et al. Polyflex stents for malignant oesophageal and oesophagogastric stricture: a prospective, multicentric study. Eur J Gastroenterol Hepatol 2007;19:195-203. 10. Holm AN, de la Mora Levy JG, Gostout CJ, et al. Self-expanding plastic stents in treatment of benign esophageal conditions. Gastrointest Endosc 2008;67:20-5. 11. Dua KS, Vleggaar FP, Santharam R, et al. Removable self-expanding plastic esophageal stent as a continuous, non-permanent dilator in treating refractory benign esophageal strictures: a prospective two-center study. Am J Gastroenterol 2008;103:2988-94. 12. Verschuur EM, Homs MY, Steyerberg EW, et al. A new esophageal stent design (Niti-S stent) for the prevention of migration: a prospective study in 42 patients. Gastrointest Endosc 2006;63:134-40. 13. Siersema PD. New developments in palliative therapy. Best Pract Res Clin Gastroenterol 2006;20:959-78. 14. Homann N, Noftz MR, Klingenberg-Noftz RD, et al. Delayed complications after placement of self-expanding stents in malignant esophageal obstruction: treatment strategies and survival rate. Dig Dis Sci 2008;53:334-40. 15. Verschuur EM, Steyerberg EW, Kuipers EJ, et al. Effect of stent size on complications and recurrent dysphagia in patients with

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esophageal or gastric cardia cancer. Gastrointest Endosc 2007;65: 592-601. Dormann AJ, Eisendrath P, Wigginghaus B, et al. Palliation of esophageal carcinoma with a new self-expanding plastic stent. Endoscopy 2003;35:207-11. Szegedi L, Gal I, Kosa I, et al. Palliative treatment of esophageal carcinoma with self-expanding plastic stents: a report on 69 cases. Eur J Gastroenterol Hepatol 2006;18:1197-201. Mayoral W, Fleischer D, Salcedo J, et al. Nonmalignant obstruction is a common problem with metal stents in the treatment of esophageal cancer. Gastrointest Endosc 2000;51:556-9. Knyrim K, Wagner HJ, Bethge N, et al. A controlled trial of an expansile metal stent for palliation of esophageal obstruction due to inoperable cancer. N Engl J Med 1993;329:1302-7. Siersema PD, Hop WC, Dees J, et al. Coated self-expanding metal stents versus latex prostheses for esophagogastric cancer with special reference to prior radiation and chemotherapy: a controlled, prospective study. Gastrointest Endosc 1998;47:113-20.

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Alimaxx-E stent for the palliation of malignant dysphagia

Received January 9, 2009. Accepted May 21, 2009. Current affiliations: Department of Gastroenterology and Hepatology (E.M.L.V., E.J.K.), Department of Public Health (E.W.S.), and Department of Internal Medicine (E.J.K.), Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands, Department of Gastroenterology and Hepatology (J.E.v.H., P.F.), Academic Medical Center, Amsterdam, The Netherlands, Department of Gastroenterology (A.R.), Instituto Clinico Humanitas, Milan, Italy, Department of Gastroenterology and Hepatology (P.D.S.) and Utrecht Palliative Care Center (M.J.U.) University Medical Center Utrecht, Utrecht, The Netherlands. Presented at Digestive Disease Week, May 17-22, 2008, San Diego, California (Gastrointest Endosc 2008:67:AB250). Reprint requests: Madeleen J. Uitdehaag, RN, MSc, Department of Gastroenterology & Hepatology, University Medical Center Utrecht, Utrecht Room F02.615, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.

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